Electronic devices such as smart phones, personal digital assistants, location based devices, digital cameras, music players, computers, or video recorders, have become an integral part of many daily activities. Key components of these electronic devices are integrated circuit devices. These tiny integrated circuits must perform during daily activities including a wide variety of environmental conditions as well as potentially damaging forces. Many and varied types of packaging, intended for protection, interconnection or mounting, have been developed for integrated circuit devices.
When the dimension of a printed circuit board becomes smaller and smaller, the available surface for placing IC components becomes smaller and smaller as well. Conventionally, a number of IC semiconductor packages are side-by-side mounted on a printed circuit board which no longer can be implemented in advanced miniature electronic products. Therefore, in order to meet the requirements of smaller surface-mounting area and higher densities of components, 3D package is proposed by vertically stacking multiple semiconductor packages. This is also called POP (Package-On-Package) device.
Including requirements for multi-functional applications as well as miniaturization of electronic devices, various technologies have been studied and developed to provide high-capacity semiconductor products. Methods for providing the high-capacity semiconductor products include increasing the capacity of a memory chip, i.e., increased integration of the memory chip. The increased integration of the memory chip may be achieved by integrating more cells into a limited space of the semiconductor chip.
In recent years, demands for system-in-package (SIP) and multi-chip package (MCP) technologies have been rapidly increasing for applications in mobile appliances. The SIP is a special form of the MCP where different semiconductor devices (e.g., DRAM, SRAM, CPU, etc.) are integrated into one package. In the SIP and the MCP, even when only one semiconductor device is defective, the package is treated as a bad package although the other semiconductor devices in the package are not defective. Therefore, it is difficult to improve production yield of these types of packages.
A package-on-package approach allows testing of individual functions prior to joining the assembly. With increased demand for high volume devices and reduced cost a balance must be struck between volume demand and manufacturing loss due to defective assemblies.
Drawbacks of conventional designs include manufacturing defects caused for example by the molding process, where leakage or flash contaminates electrical contacts or the pressure of the mold chase may damage the substrate insulator. Other issues may include integrated circuit die cracking due to reduced thickness of the mold cap in order to maintain a thin package. The thin mold cap may also attribute to warpage of the package.
With the goal of increasing the amount of circuitry in a package, but without increasing the area of the package so that the package does not take up any more space on the circuit board, manufacturers have been stacking two or more die within a single package. Unfortunately, sufficient overlap for electrical interconnect, large footprint top packages, increased device integration, pre-testing, and interconnect lengths have plagued previous package designs.
Thus, a need still remains for a stacked integrated circuit packaging system to improve area and volume. In view of the ever-increasing commercial competitive pressures, along with growing consumer expectations and the diminishing opportunities for meaningful product differentiation in the marketplace, it is critical that answers be found for these problems. Additionally, the need to save costs, improve efficiencies and performance, and meet competitive pressures, adds an even greater urgency to the critical necessity for finding answers to these problems.
Solutions to these problems have been long sought but prior developments have not taught or suggested any solutions and, thus, solutions to these problems have long eluded those skilled in the art.